This invention relates to electric storage batteries of the type having their external terminals in the side or end walls of the battery container and primarily automotive batteries which are subjected to wide temperature excursions and active jostling, bouncing and the like in use. One such battery having a recessed, threaded female terminal is disclosed in Rowls et al U.S. Pat. No. 3,775,730. Batteries of this type have their terminals beneath the electrolyte level of the battery and hence the joint must necessarily be liquid-tight to preclude the seepage of any corrosive electrolyte through the terminal. Experience has shown that reliable, liquid-tight joints are difficult to consistently produce (i.e., on a production basis) in batteries having thin-wall (i.e. about 0.100 inch or less), plastic cases. In one proposed method of assembly of side terminals (i.e., Miller U.S. Pat. No. 3,767,467), a terminal is provided with a projection which is inserted through an aperture in the case wall and mates with, and is fused to, a retaining ring on the inside of the wall. In such a process, fusing is achieved by turning the case on its side (i.e., terminals down) and gas burning the terminal and ring together. Thereafter, the case is righted, the battery innards inserted and the plate straps thereof welded to the ring (again by turning on its side) to complete the internal connection. Such connections made on a production basis have a tendancy to leak not only because the mechanical joint itself is not always tight enough to prevent leakage, but also because the heat generated during the fusings causes distortion of the plastic around the terminal and further degrades the seal. Accordingly, manufacturers of this type connection have customarily provided an additional sealant such as hot melt at the terminal-case joint to insure adequate sealing. Another approach to the manufacture of side terminal batteries has been to die cast the terminal into an aperture performed in the battery case wall. Such techniques not only require rather critical manufacturing variables and tooling but also tend to have slower production rates. Moreover, each of the aforesaid processes have a portion formed on the inside of the case wall which hinders subsequent insertion of the battery innards into the case.
It is therefore an object of the present invention to provide a fluid type side terminal battery design and assembly process which yield a highly reliable seal. It is a further object of this invention to provide a side terminal structure and assembly process which does not interfere with the insertion of the battery's innards and makes more effective utilization of the internal volume of the battery. It is a still further object of this invention to provide a side terminal battery structure and assembly process in which the connections to the battery's innards (i.e., plates and plate straps) may be made at locations remote from the wall of the case through which the terminal passes. These and other objects and advantages of the present invention will become more readily apparent from the detailed description which follows.